Cardioembolic caudate infarction as a cause of hemichorea in lupus anticoagulant syndrome.

An association exists between antiphospholipid antibodies and chorea. As these antibodies are associated with thrombosis, it has been suggested that cerebral infarction might cause chorea. However, CT and MRI typically do not demonstrate focal basal ganglionic lesions in such patients and an autoimmune mechanism for chorea has also been proposed. We report a young woman with left hemichorea and dyspnea. She was found to have lupus anticoagulant, large aortic and tricuspid vegetations, and pulmonary emboli. CT and MRI showed a small lesion in the head of the right caudate. In the presence of a definite cardiac source for emboli (valvular vegetations) with embolic activity (pulmonary emboli), it is likely that this patient's hemichorea was caused by cardioembolic caudate infarction.